The invention relates to a removable vehicle roof with an operating mechanism by way of which the roof can be moved between a closed position, in which the roof covers the vehicle interior, and a storage position, in which the roof is deposited in a storage compartment.
DE 199 60 010 C1 discloses a vehicle roof which is movable between a closed position, in which it covers the vehicle interior, and a storage position, in which the roof is deposited in a rear storage compartment. The roof is operable by an operating mechanism, which is supported on a vehicle body console and which is operable by a first hydraulic operating element. The console is pivotally supported on the vehicle body and can be pivoted by a second hydraulic operating element. This combined movement by way of the roof operating mechanism on one hand and the console supporting the roof operating mechanism on the other hand provides for a compact storage structure, but it requires the activation of two separate, energy-consuming operating elements.
DE 198 05 477 C1 discloses a convertible vehicle with a hardtop vehicle roof comprising two rigid roof parts which are supported on the vehicle body by way of a roof operating mechanism and which can be moved between the closed and the storage positions by an operating element connected to an arm of the roof operating mechanism. The roof operating mechanism is in the form of a four-link mechanism by way of which the rear roof part is supported on the vehicle body.
Such operating mechanisms have the disadvantage that, because of the relatively short length of the lever section disposed between the pivotal vehicle body support point of the roof operating mechanism and the connecting point of the control element, relatively large operating forces are needed for the transfer of the vehicle roof between its end positions. These large operating forces can easily be generated by the hydraulic operating element but the components which are engaged by the hydraulic element, that is, the roof operating mechanism and the support area on the vehicle body may be deformed by such large forces.
It is also a disadvantage that generally an advantageous lever ratio of the operating element with respect to the roof operating mechanism is present only in one of the two end positions of the vehicle roof whereas the roof has to be moved out of the other end portion with a disadvantageous lever arrangement, which requires high operating forces. As a result, the chances of applying to the vehicle components exceedingly high operating forces which may damage the components are quite high.
DE 40 26 392 A1 discloses a pop-up roof for a motor home which can be pivoted up from the vehicle body roof structure so that it is upwardly angled. The pop-up roof is raised by a roof operating mechanism, which comprises two arms, which are linked together and can be moved between a folded position and an upstanding position. In order to compensate about for the weight of the movable roof part one of the two arms of the roof operating mechanism is provided with a tension spring which is connected to a rope that extends around the joint of the two arms and which is connected with its end remote from the tension spring to the other arm. The tension spring exerts on the operating mechanism permanently a force in opening direction, that is a force which biases a roof in opening direction that is a force which biases the two arms from their folded position, in which the roof is closed, to an open position in which the roof is popped up. The spring force is active at all times in the pop-up direction of the roof, that is opposite to the weight of the roof, so that in principle only dynamic operating forces and friction forces in the bearings have to be overcome for the opening and closing of the pop-up roof. The pop-up roof is therefore biased by the spring always toward its open position.
Convertible vehicles with roofs, which can be moved into a vehicle storage compartment have the problem that the vehicle roof should be stable in its closed position and also in its storage position in which the roof is held by its weight. For the transfer between the closed and the storage positions generally an instable position of the vehicle roof has to be overcome wherein the roof and the roof operating mechanism are partially raised but are in an unstable equilibrium position. As a result, when being raised out of the closed or the storage positions, first the weight forces of the vehicle roof have to be overcome until the unstable equilibrium position is reached. Subsequently, the weight of the roof acts to move the roof into the opposite end position. Also, during this movement, a force has to be applied by an operating member, this time however in a braking direction to ensure smooth movement into the end position.
It is the object of the present invention to provide a movable vehicle roof which can be moved out of at least one of its end positions and, expediently, out of both end positions while requiring only relatively small operating forces and to achieve this with simple means.
In a removable vehicle roof supported by way of an operating mechanism on a vehicle body for movement between a closed position, in which the vehicle roof covers an interior space of the vehicle, and a storage position, in which the roof is deposited in a vehicle storage compartment, a spring element is supported on the vehicle body and connected to the roof operating mechanism in such a way as to bias the operating mechanism in each of the two end positions of the roof in a direction toward the other end position so as to facilitate movement of the vehicle roof out of each end position.
The spring element facilitates the initial movement of the vehicle roof upon raising from the respective end position so that the operating forces to be applied by the actuating element which engages the roof operating mechanism can be smaller than those used in the state of the art and the chances of deforming any components are greatly reduced.
Furthermore, the spring element counteracts the movement of the roof when approaching an end position so that the movement of the roof is slowed down in the final stage before reaching the end position and, in an ideal situation, the speed of the roof is zero when reaching the end position. The end position is therefore reached in a shock- and impulse-free way which avoids damage to the roof operating mechanism and locking components and is comfortable for the occupants of the vehicle.
The reduction of the operating forces needed for operating the roof also permits the use of a smaller operating element, which also consumes less power.
Furthermore, the manual operation of the roof is greatly facilitated if the actuating element should foil.
Expediently, the spring acts on the roof operating mechanism in each of its end positions, that is in the closed position and in storage position so as to bias the operating mechanism toward the opposite end position. To this end, two spring elements may be provided which act in opposite directions. However, in a particularly advantageous embodiment of the invention a single spring element is provided which may be a tension-compression spring, which, in one end position, is subjected to tension forces and, in the opposite end position, is subjected to compression forces. In an alternative embodiment, the spring element is subjected in each end position in the same way. This can be achieved in that the spring element is connected to a component of the operating mechanism, which, for lifting the roof from either of its end positions, is displaced in the same direction. In this case, preferably a gas compression spring is used as the spring element.
The roof operating mechanism is preferably a four-link mechanism including two links supported on the vehicle baby and an intermediate coupling link. Preferably, one of the vehicle body-supported links is used as a drive link, which is operated by the actuating element. Expediently, the second vehicle body supported link is a support link, which is engaged by the spring element. The support link is preferably a triangle link, which, at an intermediate corner, is supported on the vehicle body and is pivotally connected at the other corners to the coupling link and the spring element, respectively. The support link""s path of movement during the transfer of the roof from the closed to the storage position is essentially the same as it is during movement of the roof in the opposite direction, that is, it is a pivot movement first in one direction which is reversed to the opposite direction when the vehicle roof passes an intermediate position. This embodiment is particularly suitable for the use of a spring element, which is effective only in one direction such as a gas compression spring.
The spring element or, respectively, spring elements are expediently arranged and tuned in such a way that the resulting spring force of the spring element or, respectively, spring elements effective on the roof operating mechanism becomes essentially zero at an intermediate position of the vehicle roof between the closed and the storage positions. The operating forces required for the operation of the vehicle roof by the actuating element are minimized thereby.
Advantageous embodiments of the invention will be described below in greater detail on the basis of the accompanying drawings.